A SATA (Serial Advanced Technology Attachment) bus is a new generation of advanced technology attachment (ATA) bus, which is faster in data transmission speed and more efficient in power consumption than the conventional PATA (parallel ATA) bus. Nowadays, the SATA bus is adapted to a high-speed HDD (hard disc drive), and generally works under a scheme as shown in FIG. 1.
In the computer system shown in FIG. 1, the HDD 13 coupled to the SATA bus 12 will actively issue a state updating signal, e.g. a D2H FIS signal, when the computer system is booted. The state updating signal is transmitted through the physical layer device 123, data link layer device 122 and transmission engine 121 of the SATA bus 12, and then sent to the SATA host controller 111 disposed in the core logic chip 11 via the SATA host controller interface 14 to undergo state coordination and state updating operations. After the state coordination/updating operations have been confirmed by the computer system, the HDD 13 completes initialization and starts its normal work.
In a master/slave mode, a transmission engine 121 can be shared by two hard disc drives 23 and 24, as illustrated in FIG. 2, and both hard disc drivers 23 and 24 may issue respective state updating signals (D2H FIS signals) when the computer system is booted. The state updating signals are transmitted to the transmission engine 121 via respective physical layers 123 and 125 and data link layer devices 122 and 124. However, only one of the state updating signals will be acknowledged by the computer system because the transmission engine 121 is generally set to link to only a certain one of the HDDs when the computer system is booted, and thus the operation of the unlinked HDD might have problem. For example, the transmission engine 121 is set to link to the hard disc 23 so as to receive the state updating signal from the HDD 23 via the data link layer device 122 and the physical layer 123 upon the computer system is booted. Therefore, the computer system will respond to the HDD 23 only. On the other hand, the HDD 24, which waits too long for response from the computer system due to failure in transmitting its state updating signal to the transmission engine 121, might not enter the normal operational state. As such, the computer system may crash.